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edgewisedataby Wayne Phillips

Excel add-in · Free to use, free to modify

XL Edge: a LAMBDA library that lives in the ribbon plus more

Store, search, edit and share custom LAMBDA functions from a ribbon group instead of Name Manager — plus panel charts, Monte Carlo simulation from distributions to finished charts, and years of productivity macros.

  • Excel add-in
  • VBA
  • LAMBDA
  • Charts
  • Monte Carlo
The XL Edge tab in the Excel ribbon: a Productivity Tools group with page setup, footer and pivot commands and the Format Tools, Formula Tools and Tools menus; a LAMBDA Studio group with a filter box and dropdowns for the stored library and the LAMBDAs in the active file; and a Settings group.

Detail

Custom LAMBDA functions are powerful and almost impossible to manage. They live in Name Manager, one workbook at a time, with a text box for a formula and nowhere to record what the thing actually does. Moving a function between workbooks means copying strings by hand.

XL Edge adds a LAMBDA Studio group to the Excel ribbon: a stored library of functions with descriptions, a live dropdown, and export or import in two formats — an Excel workbook for colleagues, and the Advanced Formula Environment gist format for anyone publishing to GitHub. The library starts small on purpose, with five functions: the z-score outlier and slicer LAMBDAs from the outlier detection project on this site. The rest of the library is yours to fill.

The XL Edge tab in the Excel ribbon, showing a LAMBDA Studio group with a searchable function library and dropdowns, a Productivity Tools group, and the open LAMBDA Tools menu with its Manage LAMBDA Library submenu of options to inject, rename, describe, delete, import and export LAMBDA functions.
LAMBDA Tools → Manage LAMBDA Library: inject, rename, describe, delete, import and export.

The Tools menu opens with Create Panel Chart: a grid of small charts — one per region, product or partner — sharing a single scale, built as one native chart object rather than a dozen copies whose axes drift apart the moment the data changes. Select a block of data to build from it, or run it with nothing selected to get a placeholder block to paste over.

Next on that menu, Monte Carlo simulation. Thirty-nine distributions — thirty continuous, from normal, PERT and triangular to Student t, Pareto and the noncentral family, and nine discrete, including Poisson, geometric and Benford's law — go into the workbook as LAMBDA functions, modern versions of the distribution formulas found in tools such as XLRisk and @RISK. Five copulas make inputs move together, so price and volume or frequency and severity are not sampled as if they were unrelated. The Statistics fly-out writes a summary for one result or a table for several, plus the risk measures: Value at Risk, Conditional Value at Risk and Expected Shortfall. The Chart fly-out finishes the job with a native Excel chart — a histogram with its S-curve, an outcome histogram marked at P10, P50 and P90, or a tornado ranking the inputs. Each distribution is a non-volatile dynamic array formula: a single cell spills every trial, and the trials stay put when something unrelated recalculates, because the randomness is keyed to a seed rather than to RAND. The add-in installs only the functions a workbook uses, from its own copy, and only writes formulas, so a finished model keeps working for colleagues who only have the Excel workbook. There is no simulation loop to run — the model is ordinary array arithmetic.

The XL Edge Tools menu open on Insert Monte Carlo Distribution, between Create Panel Chart and the other Monte Carlo items: Insert Monte Carlo Copula, Insert Monte Carlo Statistics, Insert Monte Carlo Chart and Install or Update Monte Carlo Library. The distribution fly-out offers Continuous and Discrete groups; Continuous is expanded to a grid of thirty distributions, each with a small chart of its shape: beta, Cauchy, chi-squared, cumulative, Erlang, exponential, F, gamma, Gumbel, half-Cauchy, half-normal, half-Student t, inverse chi-squared, inverse gamma, inverse Gaussian, Laplace, logistic, lognormal, noncentral beta, noncentral F, noncentral t, normal, Pareto, PERT, skew normal, Student t, triangular, truncated normal, uniform and Weibull.
Tools → Insert Monte Carlo Distribution: thirty continuous and nine discrete distributions, beside the Copula, Statistics and Chart fly-outs.
An Excel chart titled Gross Profit (before returns): a histogram whose bars between P10 174.2 and P90 706.1 are orange and whose tails are grey, with dashed vertical lines labelled P10 174.2, P50 395.5 and P90 706.1.
Tools → Insert Monte Carlo Chart → Outcome Histogram, drawn from synthetic inputs.

The add-in includes additional productivity macros developed over years. All were recently refactored by Claude Code using my "excel-macro-optimizer" skill. This ensures modern coding standards are used to assist with speed, reliability, and maintainability.

It is free to use and free to modify — MIT licensed and unrestricted. No sign-up, no trial, no marketing emails.

Reference

What's on each menu

The three Productivity Tools menus. Each one is clipped to fit here — click any of them to open the full-size screenshot and read every item.